Figure 1: Two diagrams from the original manuscript of Al-Karajī's Inbāt al-miyāh al-khafiya, an influential work on hydraulics and water supply. Paper, 49 folios, in Arabic, nasta'liq script, black ink and over lining in red, 14 large diagrams in black and red. Rare Book and Manuscript Library, University of Pennsylvania, MS LJS 399, folios 32r, 35r.